Do Probiotics Prevent Gastroenteritis?

The World Health Organization defines probiotics as "live organisms which, when administered in adequate amounts, confer a health benefit on the host." Some people refer to probiotics as "soil-based" organisms, because they are derived from the soils where, in days past, humans acquired their food along with a healthy dose of symbiotic bacteria. According to "The Merck Manual of Diagnosis and Therapy," early exposure to microorganisms and allergens helps regulate your immune response and protect you from infection.

Gastroenteritis Has a Variety of Causes

Gastroenteritis is a generic term which encompasses all forms of intestinal inflammation. However, the term is usually applied to infection with any one of several viral agents, such as rotavirus or Norwalk virus, or by a bacterial organism, such as Campylobacter, Salmonella or E. coli. Depending on the pathogen involved, you can develop nausea, vomiting, diarrhea, fever, chills and body aches. The normal balance of organisms in your intestine is disrupted by a bout of gastroenteritis.

Probiotics Commonly Recommended for Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea serves as a good example of what happens when your normal gut "flora" is disturbed. When physicians prescribe antibiotics for their patients, they often recommend the use of probiotic preparations or live-culture yogurt in anticipation of diarrhea caused by the elimination of intestinal bacteria. This practice is supported by a 2007 Cochrane database review, which showed that probiotics are useful for preventing antibiotic-associated diarrhea.

Probiotics to Prevent Infectious Gastroenteritis

Probiotics have been useful for treating and preventing some forms of viral gastroenteritis, such as rotavirus diarrhea, in children, and a 2010 review in "The Journal of Nutrition" suggests that probiotics are useful for preventing traveler's diarrhea in adults. However, the authors hedge their conclusions by stating that only certain probiotics, under certain conditions, in certain "target" populations, have demonstrated benefit for these conditions.

Considerations and Recommendations

Scientific studies evaluating the use of probiotics for preventing gastroenteritis have produced inconsistent results, mainly because these trials have used different strains and doses of probiotics in different populations with different underlying causes of gastroenteritis, according to a January 10, 2010 article in "The Journal of Nutrition." Some evidence suggests that Lactobacillus rhamnosus GG, Lactobacillus casei, acidophilus and bulgaricus, Bifidobacterium bifidum and Streptococcus thermophilus and boulardii, as single agents or in combination, are useful for preventing traveler's diarrhea. L. rhamnosus GG has shown the most benefit in rotavirus diarrhea. At least 10 billion organisms daily are required to confer any benefit. Probiotics should not be administered to critically ill or immunocompromised individuals without the supervision of a physician.